You are correct, actually the LEFT JOIN should be a JOIN in this query.

I did not realize that about the YEAR selection. Thanks for pointing that out.

>I see a few problems in your query.
>
>1. Since you use LEFT JOIN with HistItems, you want to move condition on the Items table into the JOIN. See this blog post for explanations
>
>http://beyondrelational.com/modules/2/blogs/78/posts/11135/why-left-join-doesnt-bring-all-records-from-the-left-table.aspx
>
>2. Don't use DATEPART function for the year condition. Instead construct 2 dates for beginning of the year and beginning of the next year and use
>
>myDateColumn >=@StartDate and myDateColumn < @EndDate
>
>condition.
>
>See this blog post for details
>
>Bad habits to kick : mis-handling date / range queries
>
>
>>This is now my final version with Pivot. At first I was reluctant to dive into Pivot but in hindsight it's easier than I expected. The result is exactly what I need:
>>

>>SELECT Ministerie, Departement, KSC, Kostensoort,
>>		Year,
>>		ISNULL(QPivot.[1],0.00) + 
>>		ISNULL(QPivot.[2],0.00) + 
>>		ISNULL(QPivot.[3],0.00) + 
>>		ISNULL(QPivot.[4],0.00) AS Total, 
>>
>>		ISNULL(QPivot.[1],0.00) AS Q1,
>>		ISNULL(QPivot.[2],0.00) AS Q2,
>>		ISNULL(QPivot.[3],0.00) AS Q3,
>>		ISNULL(QPivot.[4],0.00) AS Q4
>>		
>>FROM (SELECT DepGroups.dgName AS Ministerie,
>>		Departments.deName AS Departement,
>>		GLSub.gsAccount AS KSC,
>>		GLSub.gsDescr AS Kostensoort,
>>		DATEPART(YEAR,Runs.ruStartDat) AS Year,
>>		DATEPART(Quarter, Runs.ruStartDat) AS Quarter,
>>		SUM(itAmount) AS itAmount
>>
>>	FROM PayEmps
>>	
>>	JOIN Departments
>>	ON Departments.DeKey = PayEmps.paDeKey
>>	JOIN DepGroups
>>	ON Departments.deDgKey = DepGroups.dgKey
>>	JOIN Runs
>>	ON Runs.ruKey = PayEmps.paRuKey
>>
>>	LEFT JOIN HistItems Items
>>	ON Items.itRuKey = Runs.ruKey
>>	AND Items.itEmKey = PayEmps.paEmKey
>>
>>	LEFT JOIN GLSub
>>	ON Items.itGsKey = GLSub.gsKey
>>
>>	WHERE PayEmps.delFlag = 0
>>			AND Runs.DelFlag = 0
>>			AND Runs.ruConcept = 0
>>			AND Runs.ruStatus = 5
>>			AND DATEPART(YEAR,Runs.ruStartDat) = ?pnYear
>>			AND Items.DelFlag = 0
>>		        AND GsAccount = '4101'
>>                        AND Runs.ruYear = 2015
>>
>>	GROUP BY DepGroups.dgName, Departments.deName, 
>>		GLSub.gsAccount, GLSub.gsDescr,
>>		DATEPART(YEAR,Runs.ruStartDat),
>>		DATEPART(QUARTER,Runs.ruStartDat)) AS QuarterlyData
>>	
>>	PIVOT(SUM([itAmount])   
>>        FOR QUARTER IN ([1],[2],[3],[4])) AS QPivot
>>
>>	ORDER BY Ministerie, Departement, KSC
>>